1. Field of the Invention
The present invention relates to a handle of a hand impact tool, e.g., a hammer, and more particularly to a hammer handle that may absorb shock by allowing the whole handle to deform.
2. Description of the Related Art
Hammer have been used for a long time and are still popular. The user's hand is subjected to shock when hammering. U.S. Pat. No. 4,331,193 to Tudisco issued on May 25, 1982 discloses a hammer handle made of a spring strip formed into an oblong closed figure and a synthetic resin handle body molded around the frame. The handle is allowed to flex for reducing the shock resulting from striking a workpiece. Nevertheless, formation of such a hammer handle is troublesome. U.S. Pat. No. 4,738,166 to Yamaguchi issued on Apr. 19, 1988 discloses a hammer having a pair of axially extending passages in a grip thereof to absorb shock by allowing the grip to deform when the hammer head strikes an object. As can be seen from FIGS. 3 and 4 of said patent, the radially extending openings are not communicated with axially extending passages and thus have an unsatisfactory shock absorbing result. U.S. Pat. No. 5,280,739 to Liou issued on Jan. 25, 1994 discloses a hammer with a hand grip having a pair of holes to allow the hand grip to be compressible and deformable such that vibrations and shocks transmitted to the hand grip can be absorbed. Nevertheless, the shock-absorbing effects provided by the hammer handles disclosed in both U.S. Pat. Nos. 4,738,166 and 5,280,739 are not satisfactory, as the shock is only transmitted and absorbed along the axial direction. U.S. Pat. No. 811,390 to Foreman issued on Jan. 30, 1906 discloses a tool handle including channels 5, orifices 7, and recesses 4 in which air entering the recesses 4 may escape via the orifices 7. The shock occurring during hammering is mainly in the vertical direction that is parallel to the longitudinal axis of the hammer head. Nevertheless, the recesses 4 and the channels 5 are too small for they are arranged along a peripheral edge of the tool handle and thus fail to provide satisfactory shock-absorbing effect. The present invention is intended to provide an improved hammer handle that mitigates and/or obviates the above problems.